import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: ${USER}
 * Date: ${YEAR}-${MONTH}-${DAY}
 * Time: ${TIME}
 */
public class Main {
    public static void login(){
        int cnt = 3;
        Scanner scan = new Scanner(System.in);
        while(cnt != 0) {
            String str;
            System.out.println("请输入你的密码:");
            str = scan.nextLine();
            if (str.equals("123456")) {
                System.out.println("登录成功!");
                break;
            }
            cnt--;
            System.out.println("密码错误" + "你还有" + cnt + "次机会, 请重新输入!");

        }
    }
    public static double max(double a, double b, double c){
        return Math.max(Math.max(a, b), c);
    }
    public static void Print(int n){
        if(n >= 10){
            Print(n / 10);
        }
        System.out.println(n % 10);
    }
    public static int sum(int n){
        if(n <= 9){
            return n;
        }
        return n % 10 + sum(n / 10);
    }
    public static  int Fib(int n){
        if(n == 1 || n == 2){
            return 1;
        }else {
            return Fib(n - 1) + Fib(n - 2);
        }
    }
    public static void main(String[] args) {
       int ret = Fib(20);
        System.out.println(ret);
    }

}